Pen



FIG. 1 is a left side view of a pen, wherein tip of pen is retracted;

FIG. 2 is a left side view thereof, wherein tip of pen is extended;

FIG. 3 is a right side view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a rear view thereof.

The broken lines in the Figures show portions of the pen which form no part of the claimed design. 

CLAIM The ornamental design for a pen, as shown and described. 